what to do with a mentally ill mum?

my mum i think is mentally ill, she used to be alcoholic and was committed into a mental hospital twice about 15 years ago when i was a child. But she never co operated with them in the hospital so no diagnoses was given. I am kind of fed up with behavior and in my opinion she is getting worse. She spends different times at night writing pages and pages of repeated incoherent sentences about the same thing she always rants about over and over again i won't bother go into explanation what she keep saying and writing. She also writes it on the wall and the fridge. She can't sit still at night or in the early morning and goes from room to room switching on and off lights maybe 20 times in a couple of minutes. And also her breathing does be faster. And she can't wait on people if they are going some where she paces and sometimes goes out the door and paces outside living the door opened. Also when I stay with her she sometimes leaves the gas on unlit and other time burns saucepan leaving it unattended to the point where it is burnt black. Then other times she takes to the bed because she has a sore head or back pain. What could i do with her when she doesn't admit there is anything wrong she thinks that it is other peoples fault and she does not see that there is something not normal. What do you think is wrong with her and what could I do.